1. Field of the Invention
The present invention relates to a stable fabric softening composition having improved dispersibility in cold water, comprising a cationic quaternary fabric softener, preferably an imidazolinium compound, and a minor amount of an aliphatic or an aromatic or alkyl substituted aromatic sulfonate as the dispersion aid.
2. Description of the Prior Art
The use of various and diverse chemical materials and particularly cationic quaternary ammonium compounds as softeners for textile products is very well known in the art. It is also well known to employ such materials for their softening effect during the laundering operation and particularly in the rinse cycle of the laundering process. This technique has been necessitated by the fact that the softeners heretofore employed, being mainly cationic in nature, are not compatible with the major type of detergent used in the washing cycle. By far, the predominating type of detergent used in home laundering processes is anionic in nature. It has been found that even traces of anionic materials results in a precipitate which greatly reduces the effectiveness of said cationic fabric softeners. This manifestation of incompatibility has necessitated the use of cationic quaternary softeners during laundering in the rinse cycle after several rinses to free said laundered fabrics of traces of anionic detergent.
Another disadvantage of the cationic fabric softeners is that many of them form viscous and/or gelatinous water dispersions which disperse with difficulty in warm or cold water. This slow dispersibility and said gelatinous particles may cause fabric staining and uneven softening. The extent of these undesirable effects depends on the water temperature, the amount of water and clothes, degree of agitation, and the consistency of the liquid softener. These undesirable effects, namely, uneven softening and staining, are particularly evident when adding viscous solutions to cold water or lukewarm water which is preferably used in the rinsing bath. In addition, a viscous product that is not readily pourable and/or water dispersible is a great inconvenience to the housewife.
It has now been found that the addition of a minor amount of an aliphatic or an aromatic or alkyl substituted aromatic sulfonate to cationic quaternary softening agents reduces the viscosity thereof and produces an opaque, homogeneous liquid which is readily dispersible in cold without adversely effecting the physical stability of said liquid or causing any loss in softening performance thereof.